Instantaneously ignitable solid fuel

ABSTRACT

AN INSTANTANEOUSLY IGNITABLE SOLID FUEL COMPOSITION COMPRISING A PERCHLORATE, A COMBUSTION SUPPORTING SUBSTANCE SUCH AS RICE BRAN, OIL MEAL, POWDERED BAMBOO AND SODIUM OXALATE, AN ADHESIVE SUCH AS DEXTRIN, A COMBUSTION BUFFER SUBSTANCE SUCH AS CLAY, CALCIUM HYDROXIDE, AND GRANULAR FOYAITE, AND A CARBONACEOUS SUBSTANCE SUCH AS POWDERED CHARCOAL, POWDERED ANTHRACITE COAL AND A POWDERED COKE HAVING ABOUT 10-15% BY WEIGHT OF VOLATILE MATTERS.

United States Patent once Patented Sept. 5, 1972 Int. Cl. 610! 5/02 US. C]. 44-17 3 Claims ABSTRACT OF THE DISCLOSURE An instantaneously ignitable solid fuel composition comprising a perchlorate, a combustion supporting substance such as rice bran, oil meal, powdered bamboo and sodium oxalate, an adhesive such as dextrin, a combustion buffer substance such as clay, calcium hydroxide, and granular foyaite, and a carbonaceous substance such as powdered charcoal, powdered anthracite coal and a powdered coke having about -15% by weight of volatile matters.

CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of my copending application Ser. No. 809,938, filed Mar. 24, 1969, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a solid fuel composition having superior ignitability and combustibility, consisting essentially of a perchlorate as an oxidizer, a combustion supporting substance such as rice bran, oil meal, powdered bamboo and sodium oxalate, an adhesive, a combustion buffer substance such as clay, calcium hydroxide and granular foyaite, and a carbonaceous substance such as powdered charcoal, powdered anthracite and powdered coke.

Description of the prior art Instantaneously ignitable solid fuels which are easily ignited by only one match stick are generally comprised of an oxidizer such as potassium nitrate or potassium perchlorate, an adhesive such as starch, grain flour and the like, a carbonaceous substance such as coal dust or powdered charcoal and, if necessary, a plastic substance such as clay, plaster, calcium hydroxide and the like, an inflammable substance such as alkali acetate, lard, grease etc. and/or a combustion catalyst such as an oxalate or acetate of manganese or copper.

However, these conventional solid fuels have numerous drawbacks. In some cases solid fuels are difficult to ignite with only one stick of matches or the primary ignition occurs without the solid fuel bursting into flame. The term primary ignition as used herein refers to the initial stage of combustion of a solid fuel caused by contacting the flame of an ignition source, such as a match stick, with the solid fuel, and the primary ignition period is the duration of the greater part of the available oxygen within the oxidizer contained in the solid fuel being consumed and is generally about one minute. In other instances excessively rapid and violent primary ignition and/or combustion occurs. In most cases, smoke and/or smell are generated during the primary ignition and/or combustion. Especially, during primary ignition and combustion, solid fuels containing semisolid or fluid hydrocarbons, such as lard or grease, generate smoke having a characteristic ordor inherent to lard or grease and are accompanied by the generation of soot. Furthermore, since lard, grease and oil are either sernifluid or fluid, the use of then as an ingredient of a solid fuel is undesirable. Thus, such well known solid fuels are not suitable for being ignited in a closed room, and the ignition must take place outdoors or in a vented enclosure.

SUMMARY OF THE INVENTION The object of the present invention is to provide an improved solid fuel, suitable for use in open or closed environments, and which is easily ignitable, for example, by only one match stick and which can be used with safety and Without risk of sparking, fiameups or uncontrolled combustion.

1 have discovered, unexpectedly in view of the prior art, that a particular critical combination of ingredients mixed in particular critical proportions is effective to provide a solid fuel which can be ignited easily and which will burn smoothly, calmly and steadily. Moreover, my particular combination of ingredients will insure that no appreciable amount of smoke and/or undesirable smells will occur during ignition and combustion of the fuel.

A perchlorate is used in an amount of from 12 to 20 parts by weight of the fuel composition to initiate combustion and to support combustion. A lesser amount of the perchlorate will result in undesirably slow ignition and/or combustion, while a larger amount will cause undesirably rapid ignition and some tendency for the fuel to spark and' disintegrate.

From 60-65 parts of charcoal, anthracite coal or coke having about 10-15% by weight of volatile matters (as that term is used in the technical analysis of solid fuels) is used as the principal carbonaceous combustible substance. Although charcoal and anthracite coal are well known fuels, the amount thereof used in my composition is critically less than that conventionally used in fuel compositions in order to control the ease of ignition and to achieve smooth, steady, calm burning by the incorporation of additional ingredients therein.

A critical additional ingredient of my composition comprises 5-10 parts by weight of a combustion supporting substance selected from the group consisting of rice bran, oil meal, powdered bamboo, sodium oxalate and mixtures thereof. Rice bran is the husk or outer covering of rice. Oil meal is the ground solid residue that remains after expressing or extracting oil from various seeds, such as cottonseeds and soybeans. These combustion supporting substances reduce the initial ignition temperature and, therefore, in combination with the perchlorate, make it possible to achieve the desired easy ignition qualities of the fuel. At the same time they promote the smooth transition of the fuel from its initial ignited state to its smooth steady-state combustion state. Further, they do not cause any appreciable smoke or smells, because of their complete combustion promoting the primary ignition with flame of the fuel.

An additional critical ingredient comprises 8-12 parts by weight of a combustion buffer selected from clay, calcium hydroxide, foyaite and mixtures thereof. This ingredient serves to regulate both the ignition of the fuel and the subsequent combustion thereof so as to prevent sparking, uncontrolled flaming and the like and to assure steady smooth combustion.

The solid ingredients can be of any suitable particle size and, in general, it is satisfactory to use particles falling within the range of 20-200 mesh.

In addition, a minor amount of a binder or adhesive substance can be used in order that the solid particles can be adhered together to form shape-retaining molded objects. A wide variety of adhesives, such as dextrin, starch, gum arabic and polyvinyl alcohol, are suitable.

A solid fuel according to the present invention is prepared 'by blending (A) an aqueous solution of 12-20 parts by weight, preferably 17-18 parts by weight, of a perchlorate selected from the group consisting of sodium perchlorate, potassium perchlorate, calcium perchlorate and mixtures thereof, (B) -10 parts by weight, preferably 8-10 parts by weight, of a combustion supporting substance selected from the group consisting of rice bran, oil meal, powdered bamboo, sodium oxalate and mixtures thereof, (C) 1-3 parts by weight of an adhesive such as dextrin, together with (D) 8-12 parts by weight, preferably about 10 parts by weight, of a combustion buffer substance selected from the group consisting of clay such as kaolin, bentonite and the like, calcium hydroxide and granular foyaite and mixtures thereof, and (E) 60-65 parts by weight, preferably about 60 parts by weight, of a carbonaceous substance selected from the group consisting of powdered charcoal, powdered anthracite coal, powdered coke having about 10-15 by weight of volatile matters and mixtures thereof, and then molding said composition to form shape-retaining objects, such as by compacting the composition to form briquettes, suitable for use as a fuel.

The combustion supporting substance, i.e. rice bran, oil meal, powdered bamboo, sodium oxalate and mixtures thereof, contains substances such as oils, waxes, etc. which evaporate at relatively low temperatures. These serve to supplement the volatile matters of the carbonaceous substance which evaporate at relatively high temperatures. Thus the combustion supporting substance lowers the primary ignition temperature of the solid fuel thereby to facilitate, in combination with the perchlorate, the primary ignition by a flame from an ignition source, such as a match, and also promotes the following combustion. The combustion buffer substance serves to adjust the flame length of the fuel during the ignition thereof by the ignition source and, simultaneously, regulates the ignition velocity as well as the combustion velocity.

The adhesive, which is utilized for bonding the ingredients of said solid fuel, can be a conventional adhesive such as dextrin, starch, polyvinyl alcohol, gum arabic and the like.

A solid fuel according to the present invention can be used in open or closed environments because it does not generate any smoke and/or smell. Furthermore, the solid fuel is easily ignitable and it will attain a smooth, calm, steady-state combustion, without erratic, rapid and violent sparks, flameups or other uncontrolled combustion. In addition, it is more economical than conventional fuels because all the raw materials used, especially rice bran, oil meal and powdered bamboo, are obtainable at a low cost.

PREFERRED EMBODIMENTS OF THE INVENTION Example 1 A mixture consisting of:

Parts by wt. Potassium perchlorate 18 Rice bran (containing 1020% of oil) 8 Dextriu 2 Was mixed with 40 parts by weight of water. Then the aqueous solution was blended with another mixture consisting of:

Parts by wt. Powdered charcoal 40 Powdered anthracite 22 Bentonite 10 The properties of the charcoal and anthracite were as follows:

V01 ti Moisle Fixed ture matter carbon Ash Charcoal, percent 5. 6 24. 4 68.0 2. 0 Anthracite, percent 3. 0 10. 5 73. O 13. 5

The mixture was molded and dried to obtain solid fuel briquettes. The solid fuel ignited easily and, after primary ignition, it rapidly transformed to a smooth, steady-state combustion. No smoke or smell was observed during the combustion.

Example 2 The following solid fuels were prepared in accordance with the same method as described in Example 1.

Sample No. 1 was ignited readily by one match stick. After about one minute of ignition with flame, the primary ignition was completed. No smoke and no smell were observed. Then, the primary ignition was followed by a steady combustion of the solid fuel.

Sample No. 2 was ignited by one match stick in like fashion. During most of the primary ignition of about one minute, a considerable amount of a white smoke was generated almost without flames, but sometimes it flamed up. However, after the primary ignition was completed, there was achieved a steady-state combustion, the same as Sample No. 1.

Rice bran comprises 10-20% of oils while it was observed that the cereal flour lacked such substance.

Example 3 In this example, 10 parts by weight of oil meal and 20 parts by weight of anthracite were used in lieu of the 8 parts by weight of rice bran and 22 parts by weight of anthracite as described in Example 1. The combustibility of the resulting solid fuel was substantially the same as in the preceding examples, except Sample No. 2 in Example 2. The oil meal contained 56% of oils.

Example 4 In this example, 8 parts by weight of powdered bamboo, 2 parts by weight of starch and 10 parts by weight of granular foyaite were used in lieu of the rice bran, dextrin and bentonite as described in Example 1. The combustion property of the solid fuel was substantially the same as in Example 1. The powdered bamboo contained 56% of bamboo wax.

Example 5 In this example, 15 parts by weight of potassium perchlorate, 8 parts by weight of sodium oxalate, 2 parts by weight of dextrin, polyvinyl alcohol or gum arabic and a mixture of 60 parts by weight of powdered anthracite and 5 parts by weight of powdered charcoal were used in lieu of 18 parts by weight of potassium perchlorate, 8 parts by weight of rice bran, 2 parts by weight of dextrin and the mixture of 40 parts by weight of powdered charcoal and 22 parts by weight of powdered anthracite described in Example 1. The combustibility of the thus obtained solid fuel was substantially the same as in Example 1. Sodium oxalate generates about 20% of CO gas upon heating.

Example 6 'In this example, a mixture of 4 parts by weight of oil meal, 6 parts by weight of powdered bamboo and 20 parts by weight of powdered anthracite were used in lieu of 8 parts by weight of rice bran and 22 parts by weight of powdered anthracite in Example 1, respectively. The combustibility of the resulting solid fuel was almost the same as in Example 1.

Example 7 In this example, a mixture of parts by weight of calcium hydroxide and 5 parts by weight of granular foyaite were used in place of parts by weight of bentonite used in Example 1. The resulting solid fuel had substantially the same combustion property as in Example 1.

Example 8 In this example, 18 parts by weight of sodium perchlorate were used in lieu of the potassium perchlorate used in Example 1. The combustion properties of the obtained solid fuel was almost the same as in Example 1.

Example 9 In this example, parts by weight of calcium perchlorate and 8 parts by weight of bentonite were used in lieu of 18 parts by weight of potassium perchlorate and 10 parts by weight of bentonite in Example 1, respectively. Almost the same combustion properties, as described in the preceding examples, were obtained in this case.

Example 10 In Sample 1 of Example 2, Example 3 and Example 6, 60 parts by weight of powdered charcoal or powdered coke having 12% by weight of volatile matters was used in place of a mixture of 40 parts by weight of powdered charcoal and 20 parts by weight of powdered anthracite. The combustion properties of the obtained solid fuel were almost the same as in Example 1.

Example 11 Example 12 In the preceding example, except Sample No. 2 in Example 2, the amounts of the perchlorates, the combustion supporting substances, the adhesives, the carbonaceous substances and the combustion buffer substances were varied in the ranges of 12-20 parts by weight, 5-10 parts by weight, l-3 parts by weight, -65 parts by weight and 8-12 parts by weight, respectively. The resulting solid fuels have substantially the same combustibility as described in Example 1.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An instantaneously and easily ignitable solid fuel composition, consisting essentially of 12-20 parts by weight of a perchlorate selected from the group consisting of sodium perchlorate, potassium perchlorate, calcium perchlorate and mixtures thereof, 5-10 parts by weight of a combustion supporting substance selected from the group consisting of rice bran, oil meal, powdered bamboo, sodium oxalate and mixtures thereof, 1-3 parts by weight of an adhesive, 60-65 parts by weight of a carbonaceous substance selected from the group consisting of powdered charcoal, powdered anthracite, a powdered coke having about 10-15% by weight of volatile matters and mixtures thereof, and 8-12 parts by weight of a combustion buffer substance selected from the group consisting of clay, calcium hydroxide, granular foyaite and rnixtures thereof.

2. A solid fuel according to claim 1, in which said perchlorate is in the range of 17-18 parts by weight, said combustion supporting substance is in the range of 8-1-0 parts by weight, said carbonaceous substance is 60 parts by weight, and said combustion buifer substance is 10 parts by weight.

3. A solid fuel according to claim 1, in which said adhesive is a member selected from the group consisting of dextrin, starch, polyvinyl alcohol and gum arabic.

References Cited UNITED STATES PATENTS 433,653 8/189O Mayer 44l7 3,385,681 5/1968 Menncn 44-17 3,133,799 5/1964 Spano 44-17 CARL F. DEES, Primary Examiner US. Cl. X.R. 44--l5 C, 16 A 

